US4924232A
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US
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Method and system for reducing phase error in a phased array radar beam steering controller
Assignee: Raytheon Co
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Filing: 1988-10-31
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Granted: 1990-05-08
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Expires: 2008-10-31
Abstract
Abstract The method and system for reducing phase error of phased array radar beam steering controllers having digitally controlled phase shifters includes the monitoring of individual digitally controlled phase shifter elements, determining an additive phase correction to reduce the number of failed phase shifter elements, determining whether said additive phase correction is achievable by comparing the stuck bit state at each said failed changers element with said additive phase correction and adjusting the phase commands to the nearest values which can be achieved if the additive phase correction is unachievable.
Inventors
- 👤 Ralph E. Hudson
- 👤 Stanley O. Aks
- 👤 Peter P. Bogdanovic
- 👤 David D. Lynch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:40
CPC Classifications
H; H01; H01Q; H01Q3/00; H01Q3/26; H01Q3/30; H01Q3/34; H01Q3/36; H01Q3/38; H01Q3/385
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
122 words
A method of reducing phase error of digitally controlled phase shifters in a beam steering controller system for phased array radar, in which phase commands for achieving a failure free-phase slope are directed to individual phase changer elements in each phase shifter, comprising the steps of: (a) detecting failure of each of said individual digitally controlled phase changer elements; (b) determining an additive phase correction which will reduce the number of failed phase changer elements; (c) determining whether said additive phase correction is achievable by comparing the stuck bit state at each said failed changer element with said additive phase correction; and (d) adjusting said phase commands to the nearest values which can be achieved when said additive phase correction is unachievable.
Claim 2
Independent Claim
122 words
A method of reducing phase error of digitally controlled phase shifters in a beam steering controller system for phased array radar, in which phase commands for achieving a failure free-phase slope are directed to individual phase changer elements in each phase shifter, comprising the steps of: (a) detecting failure of each of said individual digitally controlled phase changer elements; (b) determining an additive phase correction which will reduce the number of failed phase changer elements; (c) determining whether said additive phase correction is achievable by comparing the stuck bit state at each said failed changer element with said additive phase correction; and (d) adjusting said phase commands to the nearest values which can be achieved when said additive phase correction is unachievable.
Claim 3
Dependent Claim
138 words
The method of claim 1, wherein said determining whether said additive phase correction is achievable comprises evaluating a discriminant defined as: F(k,i)∩(a(k,i)⊕S(k,i)) where i is the bit level of the phase changer of the kth radiating element phase shifter; F(k,i) is a failure indicator; F=0 indicates no failure; F=1 indicates a failure; a(k,i) is the commanded value of the bit; S(k,i) indicates how the phase changer has failed; S=0 indicates: the phase changer is stuck low S=1 indicates the phase changer is stuck high where [F i ∩(a i ⊕S i )] k =0 indicates a ik =S ik so that there is no error and the commanded value is achievable; and [F i ∩(a i ⊕S i )] k =1 indicates a ik ≠S ik so that there is an error and the commanded value is unachievable.
Claim 4
Dependent Claim
40 words
The method of claim 1 wherein when the nearest value adjustment has been made on one side of the antenna center and the opposite side of the antenna has no error, an equal error is introduced on said opposite side.
Claim 5
Dependent Claim
29 words
The method of claim 1, wherein said phase commands are each represented in binary form, with each binary weight class corresponding to a different additive amount of phase shift.
Claim 6
Dependent Claim
17 words
The method of claim 1, wherein the average phase slope and the commanded phase slope are equal.
Claim 7
Dependent Claim
17 words
The method of claim 1, wherein the mean square deviations about the command phase slope are minimized.
Claim 8
Dependent Claim
26 words
The method of claim 1, wherein a uniform weighting is added to said commanded phase slope to minimize the number of erroneously positioned phase changer elements.
Claim 9
Dependent Claim
18 words
The method of claim 4, wherein said corrections are applied implementing the most significant bit failure correction last.
Claim 10
Dependent Claim
16 words
The method of claim 4, wherein there are five binary weight classes of phase changer elements.
Claim 11
Independent Claim
127 words
A system for reducing phase error of digitally controlled phase shifters having individually digitally controlled phase changer elements, for use in combination with a beam steering controller system for phased array radar, comprising, (a) means for detecting failure of each of said phase changer elements; (b) means for determining failure free phase shift commands for said phase changers; (c) means for determining an additive phase correction which will reduce the number of failed phase changer elements; (d) means for determining whether said additive phase correction is achievable by comparing the stuck bit state at each said failed changer element with said additive phase correction; and (e) means for adjusting said phase commands to the nearest values which can be achieved when said additive phase correction is unachievable.
Claim 12
Independent Claim
127 words
A system for reducing phase error of digitally controlled phase shifters having individually digitally controlled phase changer elements, for use in combination with a beam steering controller system for phased array radar, comprising, (a) means for detecting failure of each of said phase changer elements; (b) means for determining failure free phase shift commands for said phase changers; (c) means for determining an additive phase correction which will reduce the number of failed phase changer elements; (d) means for determining whether said additive phase correction is achievable by comparing the stuck bit state at each said failed changer element with said additive phase correction; and (e) means for adjusting said phase commands to the nearest values which can be achieved when said additive phase correction is unachievable.
Claim 13
Dependent Claim
142 words
The system of claim 10, wherein said means for determining whether said additive phase correction is achievable comprises means for evaluating a discriminant defined as: F(k,i)∩(a(k,i)⊕S(k,i)) where i is the bit level of the phase changer of the kth radiating element phase shifter; F(k,i) is a failure indicator; F=0 indicates no failure; F=1 indicates a failure; a(k,i) is the commanded value of the bit; S(k,i) indicates how the phase changer has failed; S=0 indicates the phase changer is stuck low S=1 indicates the phase changer is stuck high where [F i ∩(a i ⊕S i )] k =0 indicates a ik =S ik so that there is no error and the commanded value is achievable; and [F i ∩(a i ⊕S i )] k =1 indicates a ik =S ik so that there is an error and the commanded value is unachievable.
Claim 14
Dependent Claim
16 words
The system of claim 10, wherein there are five binary weight classes of phase changer elements.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-07 | 1993-11-06 | 1994-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-07 | 1997-11-06 | 1998-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-07 | 2001-11-06 | 2002-05-08 | $7700.00 | Window Closed / Lapsed |